Commentary

Pain is not always well controlled after surgery.1 This can make patients anxious and reluctant to mobilise and take deep breaths, which can increase the risk of postoperative
complications, such as chest infection and deep venous thrombosis. Although paracetamol is sometimes dismissed as a weak analgesic,
partly because it is available over the counter, the review by Barden et al clearly shows that it can be an effective analgesic for moderate to severe pain after surgery. The results for dosages of
600/650 mg and 975/1000 mg were based on larger numbers of patients than other dosages assessed and therefore are more robust.

Although paracetamol is associated with potentially serious adverse events (up to half of the cases of liver failure in the
UK are thought to be the result of paracetamol),2 such consequences are rare in therapeutic use.

Paracetamol is a relatively inexpensive drug, which is widely available as a generic preparation. It is a useful analgesic
after surgery for patients with contraindications to non-steroidal anti-inflammatory drugs (eg, patients with asthma or peptic
ulcer). The number needed to treat (NNT) to achieve ⩾50% pain relief over 4–6 hours of 3.8 for paracetamol, 975/1000 mg (95%
CI 3.4 to 4.4) compares well with aspirin, 600/650 mg, which has an NNT of 4.4 (CI 4.0 to 4.9).3 Ibuprofen, 400 mg, has an NNT of 2.4 (CI 2.3 to 2.6).3 Interestingly, the NNT for morphine, 10 mg intramuscularly, is 2.9 (CI 2.6 to 3.9).3 The newer Cox-2 inhibitors seem promising for managing acute pain, with rofecoxib, 50 mg, having an NNT of 1.9 (CI 1.8 to
2.1).3

Overall, paracetamol is a useful analgesic after surgery and can be helpful when providing balanced postoperative analgesia.4